Though it becomes apparent very early on in the novel, as early as the trial where they were almost flirting with each other, that Charles is in love with Lucie, he does not mention a word of it to her until he speaks with her father, "I have had the happiness, Doctor Manette, of being so intimate here, for some year and a half, that I hope the topic on which I am about to touch may not" (Dickens, Two Promises)
The morality of Charles Darnay is also represented when he returns to France after the revolution had began, knowing full well that it would be extremely dangerous, to try and help Gabelle in Paris. This decision seems incredibly selfless upon first glance. But upon closer examination, it is incredibly foolish and did not take into account how Lucie and Little Lucie would feel about him leaving in the middle of the night. .
Sydney Carton, a man who looks almost exactly like Darnay, is meant to represent darkness and outward immorality. He also makes his first appearance at Darnay's trial, though he does not testify. In fact, the strong resemblance between Carton and Darnay is the main reason that Darnay was acquitted. We also see Carton interacting with Mr. Stryver, Darna's attorney. He is a spectator at the trial, described as having"something especially reckless in his demeanor,"" that "gave him a disreputable look"" and having a manner that "was so careless as to be almost insolent" (Dickens, Disappointment). Carton is also compared to a jackal, a South African mammal that is known for living in a small group. Jackals are very territorial of their pack and go to great lengths to protect them. Carton is a deeply misunderstood character, seeming like the man who was always tipsy at the very least, "Sydney was none the livelier and none the soberer for so much application. It had taken a deal of extra wet-toweling to pull him through the night; a correspondingly extra quantity of wine had preceded the toweling; and he was in a very damaged condition" (Dickens, A Companion Picture).
